I know I'm not the first to tell you about the benefits of exercise. I also know I'm not the first to tell you that exercise can do a body good from both an emotional and physical standpoint.
But I might be the first to tell you that exercise, and specifically the aerobic kind that gets your heart rate up for an extended period of time, can improve your sleep. If you're an insomniac, listen up: a new study from Northwestern Medicine that will be published in the journal Sleep Medicine soon showed serious promise to the dramatic effects of exercise on people diagnosed with insomnia.
Millions of Americans suffer from symptoms of chronic insomnia, including difficulty falling asleep and/or staying asleep, and impaired daytime functioning. Insomnia also tends to strike more severely during middle-age and older adults. Women have the highest prevalence of insomnia. Many of these people resort to prescription drugs and sleep aids to help achieve a better night's sleep. But drugs are not always a solution over the long-term, and there's no substitute for exercise, which has benefits that go far beyond restful sleep.
The highlights from the study:
- Twenty-three sedentary adults, primarily women 55 and older with insomnia, were divided into two groups: one that would commence an exercise program and another that would engage in less physically demanding activities. Both groups received education about good sleep hygiene, which includes sleeping in a cool, dark and quiet room, going to bed the same time every night, and not staying in bed too long if you can't fall asleep.
- The aerobic physical activity group exercised for two 20-minute sessions four times per week, or one 30- to 40-minute session four times per week, both for a total of 16 weeks. Participants worked at 75 percent of their maximum heart rate on at least two activities, including walking or using a stationary bicycle or treadmill.
- Participants in the non-physical activity group participated in recreational or educational activities, such as a cooking class or a museum lecture, which met for about 45 minutes three to five times per week for 16 weeks.
The people in the exercise group fared far better than the non-exercise group when it came to their sleep. Exercise not only improved their sleep quality -- elevating them from being a "poor sleeper" to a "good sleeper," but they also reported feeling better. Their moods improved, and they had more vitality and less daytime sleepiness.
I've long been an advocate for getting plenty of physical activity into your life to promote restful sleep. This study may have been among the first to examine the benefits of maintaining an aerobic regimen among insomniac women, but it certainly wasn't the first to discover the profound role exercise has in supporting high-quality sleep.
Not everyone experiences the same sleep benefits of exercise, but people who suffer from insomnia aren't usually the athletes and highly active individuals. (The only instance I've seen is where athletes over-train and for some reason have a hard time turning their mind off at night, or they are so used to exercising that on their "off days" their body craves that exercise to help with sleep.) To the contrary, most people who complain of sleep problems lead sedentary lives and don't practice a regular exercise routine.
Aerobic exercise has shown to aid in sleep primarily by doing two things: 1) helping you fall asleep quicker; and 2) plunging you into deep (or delta) sleep for a longer period of time, which is where you need to be to feel refreshed and restored the next day. Other studies on people who participate in aerobic activities show that they have a tendency to secrete more growth hormones at night, which aids in repairing and rejuvenating the body. And let's not forget the stress component to exercise: getting active tends to help us lower our stress levels, which allows us to calm down enough to welcome sleep!
One of the current reasonings behind exercise's effects on sleep centers of the brain is the thermogenic hypothesis, which states that exercise promotes sleep by heating the body or brain. When you work out (it has to be an aerobic workout for at least 20 to 30 minutes), your body's core temperature rises a couple of degrees (about 2oF) and stays that way for about four to five hours. When it cools back down, your core temperature will decrease to a point lower than had you not worked out at all. And it's this drop in body temperature that is theorized to promote falling asleep and gaining the deep, sound sleep your body needs.
Exercise your body to rest your body. It's as simple as that.
Michael J. Breus, Ph.D.
The Sleep Doctor™